8638021 has 4 divisors (see below), whose sum is σ = 9872032. Its totient is φ = 7404012.

The previous prime is 8637991. The next prime is 8638033. The reversal of 8638021 is 1208368.

8638021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8638021 - 2⁹ = 8637509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8638051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 616995 + ... + 617008.

It is an arithmetic number, because the mean of its divisors is an integer number (2468008).

Almost surely, 2^8638021 is an apocalyptic number.

It is an amenable number.

8638021 is a deficient number, since it is larger than the sum of its proper divisors (1234011).

8638021 is a wasteful number, since it uses less digits than its factorization.

8638021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234010.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 8638021 is about 2939.0510373248. The cubic root of 8638021 is about 205.1814455419.

The spelling of 8638021 in words is "eight million, six hundred thirty-eight thousand, twenty-one".